1. Field of the Invention
This invention relates to a dispensing assembly for administering high purity liquid processing chemicals in a production line. More particularly, this invention relates to a dispensing assembly of the character described which can be safely purged of residual chemical, refilled, and reused in the production line.
2. Description of the Art
The production of certain high tech components, such as semiconductors, or the like, may involve the use of ultra high purity liquid chemicals, such as photoresists, to process the components. These chemicals are applied to the components either in a liquid or a vapor form in a closed processing station. The chemicals are dispensed into the processing station from liquid chemical containers which are removably connected to the production line. The liquid chemical may be forced out of the container either by means of a piston which telescopes into the container, or by means of a pressurized stream of an inert gas such as nitrogen, which is fed into the container. When the liquid chemical container has been emptied of the liquid chemical, it is disconnected from the production line and replaced by a filled container.
The problem of safely disposing of the emptied liquid chemical containers in an environmentally safe fashion has proven to be expensive and has not been satisfactorily solved. When the liquid chemical containers are glass, they cannot be recycled safely without washing because of the chemical residue that invariably remains inside of the container. The washing procedure is expensive and time-consuming. Where plastic containers or plastic pouches are used to hold the liquid chemical, recycling of the plastic container material in an environmentally safe fashion cannot be done. Thus the disposal of these containers is a problem which the semiconductor and other related industries have not satisfactorily resolved.